Sadie knows. The dog always knows not to go into the haunted house.
But since this was 1971, and the world, much less Rhode Island's Perron family, had not seen "The Exorcist" and the generations of ultra-realistic horror movies and "Ghost Hunters" TV shows that followed, they didn't know to...

But since this was 1971, and the world, much less Rhode Island's Perron family, had not seen "The Exorcist" and the generations of ultra-realistic horror movies and "Ghost Hunters" TV shows that followed, they didn't know to heed the dog's warnings. The Perrons were in for it.

"The Conjuring" is like a prequel to 40 years of demonic possession thrillers, a movie about the original ghost hunters, Ed and Lorraine Warren, and an early case that this "Amityville Horror" couple found so terrifying they never talked about it - "until now!"

James Wan, who made his horror bones with "Saw" and outgrew torture porn with the superbly spooky "Insidious," reunites with his "Insidious" star Patrick Wilson for this solid and sometimes hair-raising thriller about a haunted house, the family of seven haunted by it and the can-do couple summoned by the Perrons.

The Warrens lecture at colleges, show film of inexplicable supernatural events and collect the actual possessed artifacts that they weed out among all the false alarms that are too often just creaking pipes and settling floorboards. Lorraine (Vera Farmiga) is clairvoyant, which means she sees what those truly spooked see and feels what they feel. Ed (Wilson) may be credulous, but he's the pragmatist - applying 1960s and '70s pre-digital technology to his search for "proof" of what they're dealing with.

He's got a ready answer for dealing with their problem when Carolyn and Roger Perron (Lili Taylor and Ron Livingston) invite them over. Are their kids baptized?

"We're not really a church-going family."

"You might want to rethink that."

The humor in "The Conjuring" comes from the naivete of the victims. Carolyn doesn't recognize her bruise marks as demonic injuries. Their five daughters don't know that their invisible friends, their sleepwalking companions and the mysterious bumps and claps that ruin their games of "Hide and Clap" are ghosts.

Wan and his screenwriters serve up some classic scary situations and provide a decent jolt or three in the "sealed-off basement," the ghostly shadow in the mirror of an antique jack-in-the-box. There's something particularly insidious about a monstrous menace to children.

But Farmiga and Wilson play the Warrens as slow to take on urgency, with a seen-it-all world weariness that robs some scenes of their true terror.

And horror audiences are more sophisticated than this story. A movie that plays like horror's greatest hits - a little "Exorcist" here, a dose of "Chucky" or "Paranormal Activity" there - is going to feel tired, even with the odd surprise.

It conjures up a few frights, but "The Conjuring" is more solid than sensational and spine-tingling. Think of it as a horror history lesson, the original "based on a true story" to explain those things that go bump in the night.